we all know we need a clean energy economy, where it's really, really cheap to buy the energy and where the energy that you're buying is not polluting the atmosphere. not causing a greenhouse gasses that are driving up the temperature and producing droughts and is not producing a number of other health-related effects from air pollution. we all know this. we know what we're after. how we're going to get there? the way we discovered in the book is, it's pretty simple. could you have the federal government buy all the new things that are necessary and then give them away? not practical. not going to happen. we don't have that kind of capability in the federal government to add the deficit. so you have to open the door to private investment to do this job of rebuilding the power platform in the united states. >> host: and the technology aspect of that is? >> guest: technology aspect is manifold. and price performance improves every 18-24 mocks. in the last year we have gotten into the innovation cycle in batteries so by the end of 2020 electric vehicles will actually be price competitive w